Fix cropped floating gesture candidate window

ui/keyboard/keyboard_ui.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_KEYBOARD_KEYBOARD_UI_H_
 #define UI_KEYBOARD_KEYBOARD_UI_H_
 
 #include "base/macros.h"
 #include "ui/base/ime/text_input_type.h"
 #include "ui/keyboard/keyboard_export.h"
@@ skipping 18 matching lines @@
   KeyboardUI();
   virtual ~KeyboardUI();
 
   // Gets the virtual keyboard window. May return null if the window has not yet
   // been created.
   virtual aura::Window* GetKeyboardWindow() = 0;
 
   // Whether the keyboard window has been created.
   virtual bool HasKeyboardWindow() const = 0;
 
+  // Whether this window should do an overscroll to avoid occlusion by the
+  // virtual keyboard. IME windows and virtual keyboard windows should always
+  // avoid overscroll.
+  virtual bool ShouldWindowOverscroll(aura::Window* window) const = 0;
+
   // Gets the InputMethod that will provide notifications about changes in the
   // text input context.
   virtual ui::InputMethod* GetInputMethod() = 0;
 
   // Shows the container window of the keyboard. The default implementation
   // simply shows the container. An overridden implementation can set up
   // necessary animation, or delay the visibility change as it desires.
   virtual void ShowKeyboardContainer(aura::Window* container);
 
   // Hides the container window of the keyboard. The default implementation
@@ skipping 36 matching lines @@
 
  private:
   keyboard::KeyboardController* keyboard_controller_;
 
   DISALLOW_COPY_AND_ASSIGN(KeyboardUI);
 };
 
 }  // namespace keyboard
 
 #endif  // UI_KEYBOARD_KEYBOARD_UI_H_